If you've ever experienced the flashes of light, blind spots, and decreased vision that can precede a migraine, you know they are a scary and disorienting warning of the pain ahead. Doctors are not yet sure if these visual disturbances, known as ocular migraines, trigger the migraine pain or if they are a symptom of it, but many of the 30 million Americans who suffer from migraines have reported seeing "auras."

The mechanisms that cause migraines are not fully understood, which is one reason why they're so tough to treat. And many of the current drug regimens are slow to take effect, are not effective at all for up to 40 percent of users, or are designed for related conditions, such as high blood pressure rather than migraines themselves. Another issue: Migraines can recur frequently, making treating them with strong opioids and painkillers concerning and potentially dangerous.

The good news? Medical marijuana and cannabis-derived products like hemp oil provide new hope for those suffering from debilitating headaches. Here's everything we know about the science of cannabis for the treatment and prevention of ocular migraines:

The basics of ocular migraines: subtypes and symptoms.

For starters, did you know there are two kinds of ocular migraines? The first is migraine with aura, and the second is a retinal migraine. Migraines with aura are the more common type, with about 30 percent of migraine sufferers experiencing these visual disruptions. Typically, the aura precedes a full-blown migraine by about 30 minutes to an hour and can include flashes of light and blind spots in both eyes and sometimes difficulty speaking. Auras are believed to stem from abnormal electrical activity in the brain and are not permanent.

Retinal migraines, on the other hand, are characterized by visual disturbances in just one eye, decreased vision, and temporary vision loss. These symptoms precipitate from electrical activity directly in the retina. Retinal migraines are less common, but they are more serious and in rare cases can result in permanent vision loss.

If you experience migraines accompanied by visual disruptions, especially when in only one eye, consult with your primary care physician and consider seeing an ophthalmologist. They can help you rule out other more serious conditions and help you manage symptoms.

Endocannabinoid deficiency and migraines.

Recently, it has come to light that the endocannabinoid system, a network of neurotransmitters and cannabinoid receptors, plays a major role in our central nervous system and may influence migraines. The endocannabinoid system interacts with and regulates levels of endogenous (meaning they are produced inside our bodies naturally) cannabinoids. These cannabinoids bind to and activate different cannabinoid receptors in the body. One of these receptors, CB1, is found in parts of the brain and nervous tissue responsible for regulating pain signaling. Research has shown that when endocannabinoids activate CB1 receptors, it can inhibit this signaling pathway and suppress pain.

Therefore, low levels of endocannabinoids may result in decreased pain tolerance. Chronically low cannabinoid levels, also known as clinical endocannabinoid deficiency (CED), is believed to play a role in causing hyperalgesia conditions like migraines, fibromyalgia, and irritable bowel syndrome. In fact, a study looking at the endocannabinoid anandamide found that those who suffered from migraines had significantly less anandamide in their cerebrospinal fluid than those who did not experience migraines. Meaning: Low endocannabinoid levels could be the root of your migraine pain.

Additionally, cannabinoids (or the lack of) may play a role in the auras that precede migraines. Auras are believed to be caused by cortical spreading depression (CSD), a wave of electrophysiological hyperactivity, brought on by glutamate overstimulation. Essentially, the neurotransmitter glutamate fires too many times, exciting the neurons and causing abnormal electrical activity to dissipate across the brain. One of the roles of cannabinoids in the brain is to suppress glutamate signaling to ensure this buildup doesn't occur. When cannabinoids are low, this system can fail, leading to the generation of auras and potentially triggering a migraine.

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Hemp oil for ocular migraines.

An increasing number of scientists believe that supplementing with phytocannabinoids, cannabinoids found in plants, may balance cannabinoid levels in the body and decrease the occurrence of migraines. The most well-known source of phytocannabinoids is the cannabis plant, which includes hemp and marijuana. These plants contain over 100 types of cannabinoids, some of which have medicinal properties, like CBD, and some of which you know about for their psychoactive effects, like THC. Cannabinoids can be extracted from hemp and marijuana in the form of oils. Hemp oil typically contains less than 0.3 percent of the psychoactive cannabinoid THC and will not get you high—but it may help ward off your ocular migraine. It can be consumed as tinctures, pills, lotions, or even in edible goodies like chocolate. Since studies are still in the early stages there are no standard doses, but mbg collective member and functional medicine practitioner Dr. Will Cole suggests starting with 10 milligrams and working your way up until you find what works for you.

Cannabis has actually been used medicinally to treat pain and migraines since at least the sixth century, but due to regulations and an association with marijuana, clinical studies of hemp-derived products have been limited. There have been some small, but promising, studies on humans and animals testing the efficacy of hemp oil for pain management in the past few decades. In one study, CBD oil, a cannabinoid derived from hemp oil, was found to be more effective than a common migraine medication at preventing attacks, and it led to fewer side effects.

As cannabis and hemp become more widely accepted, we expect to see a lot more studies confirming its therapeutic powers. The endocannabinoid system and hemp oil could be an important piece of the puzzle of conquering migraines and ending those frightening auras.